Received: by 2002:a25:31c3:0:0:0:0:0 with SMTP id x186csp637777ybx; Wed, 30 Oct 2019 02:36:06 -0700 (PDT) X-Google-Smtp-Source: APXvYqxBKEhioBpXYVzaIIjOl4yl9czbI76Slec4otdFh4Y2/QqIICspyXBXvdWOPBeKs6O06aMe X-Received: by 2002:aa7:d6da:: with SMTP id x26mr17279208edr.183.1572428166879; Wed, 30 Oct 2019 02:36:06 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1572428166; cv=none; d=google.com; s=arc-20160816; b=mpvkAbc6Vf3HBhcvDdO8r75ApxXq6tOv+e/Tn4uI2u3w+rUdLcmA1aKGwTFZimqkAE 5p0UKK2OuQZxToFRr8nraA5w13VcBj9OM776Qk1zI1pCF36jgabamRqThGAgkxUzmeDe bvSZcHOKRFYTZjQBBxgDN4zFy94CQzlcM12DUiWe2KJGA/jX4mfZYaKtX+MBRqjqqmSf fh1ilYQQ1FvSbPDGd0FEUMOZZSWzKsF5t7l3e2aPZdhZRA9msXOSywxaNZ9ttlHO/0nN 9xsANOrN8WpYhHgQS9Ply+7xwz1pQS4Nt8vO/B/xzayNXj0o8e0vEhrQnOUOKb/I1gli EEgA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:content-transfer-encoding :content-language:accept-language:message-id:date:thread-index :thread-topic:subject:cc:to:from; bh=ZxUoJthras37eMnIC6JR7OAO058EXyx8ZOGrdgAtO0U=; b=w9KG8R3ZjntQuYPRqvSe/fqUHQ+4X730v6k/8Ps8bF3XRGzKvOq/bzP71M4dBGQEzS LfneHvz20MpUSJHYULAXMqk8VRiHBDa3lJl8QkXfXyq+ZebfDo1O0SL8n0NQU45VOnyz k7SUDpGXQzSs1/p0vhv8MLiJNOce44s6m+jZ3ZsE1jsrTXAErXj2ZA/CdN48XMX8RCn2 SDXE/2VH62u6U+JqHPdV97DJMaFmM1w6NwhUmvBw9uQZv6iQGA4JVqwZvX5kBEDkdUYk HjMPUKhx0IF7IOXLfpsx6AzZZx8Gbm1ZrASWSXirkR9J9Gi7vAV8PONtuXsMM0W/kgjx C0GQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id gg9si796673ejb.438.2019.10.30.02.35.43; Wed, 30 Oct 2019 02:36:06 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726262AbfJ3Jcr convert rfc822-to-8bit (ORCPT + 99 others); Wed, 30 Oct 2019 05:32:47 -0400 Received: from mx21.baidu.com ([220.181.3.85]:52083 "EHLO baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726028AbfJ3Jcr (ORCPT ); Wed, 30 Oct 2019 05:32:47 -0400 Received: from BJHW-Mail-Ex14.internal.baidu.com (unknown [10.127.64.37]) by Forcepoint Email with ESMTPS id 38CB867CA021E; Wed, 30 Oct 2019 17:32:40 +0800 (CST) Received: from BJHW-Mail-Ex13.internal.baidu.com (10.127.64.36) by BJHW-Mail-Ex14.internal.baidu.com (10.127.64.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 30 Oct 2019 17:32:41 +0800 Received: from BJHW-Mail-Ex13.internal.baidu.com ([100.100.100.36]) by BJHW-Mail-Ex13.internal.baidu.com ([100.100.100.36]) with mapi id 15.01.1713.004; Wed, 30 Oct 2019 17:32:41 +0800 From: "Li,Rongqing" To: "linux-kernel@vger.kernel.org" CC: "tj@kernel.org" , "lizefan@huawei.com" , "hannes@cmpxchg.org" , "cgroups@vger.kernel.org" Subject: mount cgroup with "already mounted or cgroup busy" Thread-Topic: mount cgroup with "already mounted or cgroup busy" Thread-Index: AdWPA9906A1LJjv0Rpi5m0VcmmdBIA== Date: Wed, 30 Oct 2019 09:32:41 +0000 Message-ID: <11be9352e1e54ebebad078b1dac7b670@baidu.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.22.198.13] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi: I meet a issue, and not sure if it is normal Using the below script, the last line mount will fail after unmount And it will fail until reboot system mount -t cgroup -o cpu,cpuset xx cgroup mkdir cgroup/x rmdir cgroup/x umount cgroup mount -t cgroup -o cpu xx cgroup mount: xx already mounted or cgroup busy but if I add sleep, it will success mount -t cgroup -o cpu,cpuset xx cgroup mkdir cgroup/x rmdir cgroup/x sleep 10 <<<<========== umount cgroup mount -t cgroup -o cpu xx cgroup - Li RongQing